Forming-machine for tungsten filaments.



J. W. HOWELL. FORMING MACHINE FOR TUNGSTEN PILAMENTS.

APPLICATION FILED MAY 7, 1908.

Patented May 20, 1913.

'4 SHEET S-SHEET 1.

Fig. l.

Fig.2.

J. W. HOWELL. FORMING MAGHINE FOR TUNGSTEN FILAMENTS.

APPLICATION FILED MAY 7, 1908.

Patented May 20, 1913.

4 BHEETS-SHEET 2.

lnventor John W. Hoe! I,

J. WQHOWELL. FORMING MACHINE FOR TUNGSTBN PILAMENTS.

APPLICATION FILED MAY 7, 1908.

1,062,21 Patented May 20, 1913. 4 SHEETSSHEET a.

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J. W. HOWELL. FORMING MACHINE FOB. TUNGSTEN FILAMENTS.

APPLICATION FILED MAY 7, 1908.

Patented May 20, 1913.

4 SHEETS-SHEET 4.

To all whom) may concern: 7

I UTED STATES PATENT oFFioE.

JOHN HOWELL, OF NEWARK, NEW JERSEY, ASSIGNOR TO GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK.

FORMlNG-MACHINE FOR TUNGSTEN FILAMENTS;

Specification of Letters gaten't. t t M 2 9 g Application filed May 7,1908. Serial 1\To. 431,323.

Be it known that I, JOHN W. HOWELL,

. a citizen of the United States, residing at Newark, county of Essex,State of New Jersey, have invented certain new and useful Improvementsin Forming-Machines for Tungsten Filaments, of which the following is aspecification.

My invention relates to machines for making incandescent lamps, and moreparticu larly to machines for reducing, purifying and sinteringfilaments made'of refractory material, such as'tungsten, and requiringcomparatively prolonged heating in an atmosphere of definite chemicalcomposition. This process of reducing, purifying and sintering is calledforming.

Incandescent lamp filaments of refractory metal, such as tungsten, areoften prepared by mixing thepowdered material With some binder toproduce a plastic mass which is. shaped and'then rendered partiallyconducting by being heated at a high temperature; in asuitableat-mosphere. The carbonized filament is then keptin a reducingatmosphere and heated by passing a current of electricity through ituntil the carbon is completelyremoved and only the pure tungsten orother refractory metal remains.

The object of my invention is to provide a simple and easily operatedmachine in which the filaments can be formed rapidly and accurately byunskilled labor and in atmosphere around the filaments and to which noskill on the part of the operator is required in order to maintain theproper secure the proper heatingof the filaments.

In carrying outmy invention aplurality of tormingreceptacles are mountedon a carrier which is moved intermittently and holds each receptaclestationary in front of the operator long enough to permit the removal ofthe finished filament and the insertion of a raw filament. The movementof the carrier automatically controls the con nections of thereceptacles to the sourceof supply of the forming gas which constitutes.the reducing atmosphere, and simultane-Q ously controls the amourt ofcurrent flowing through the filaments toheat them to the requireddegree, The machine is preferably arranged to' cause the forming gas toflow through the receptacle insuccession when the carrier is stationary,while the electrical connections through the filaments are broken andthe supply of forming gas is out 01f during the movement of the carrier,from one position .to another. The only duty otthe operator is to removeand re place filaments, and inorder to facilitate the operators work asmuch as possible the forming receptacles are preferably made so they maybe easily raised to leave the filament supports and-clamps easilyaccessible. The amount of current flowing through any filament may .bevaried independently of the other filaments by changing an adjustableresistance in series with it, and an ammeter arranged'to show the amountof current in any desired filament is provided to enable completecontrol of the operations to be maintained.

My invention will best be understood in connection with the accompanyingdrawings, which are merely illustrative of one .form in which theinvention may be emis a plan view of the'stationary seat of the gasvalve; Fig. 6 is a cross-section along the line 66 of the valve seatshown in Fig. 5;

Fig. 7 is aisection through one of the forming receptacles showing afilament in position for forming; Fig. 8 is a cross-section of a formingreceptacle at right angles to the plane of Fig. 7 Figs. 9 and 10 areplan and .side views respectively of the clamps for holding thefilaments; Figs. 11, 12 and 13 are detail views ofthe intermittentgearing for giving a step by step movementto the forming receptacles;Figs. 14 and 15 are plan and side views of adjustable resistances forvarying the heating current through the filaments; Fig. 16 is a planview of the Geneva stop motion which moves the forming receptaclesdefinite distances and holds. them stationary between movements; Fig. 17is a pl an View of the automatic switch for cont-rolling the heatingcurrent through-the filaments; Figs. 18 and 19 are plan and sectionalviews respectively of the plug switch for cuttingan ammeter into circuitwith the flow of current through the filaments to from one heat them iscontrolled by an automatic switch 4 carried on and rotating with themovable carrier 2, whilethe supply of forming gas which furnishes thereducing atmosphere for the filaments is controlled by an automaticvalve consisting of a rotary valve disk 5 moving with the carrier 2 andcooperating with a fixed valve seat 6 which has inlet and outlet portsfor the forming .gas. A stationary standard or support 7 carries part ofthe automatic switch 4, while the other part of the automatic switch,the carrier 2 andfthe valve disk 5 are moved position to the next andlocked'in each position by means of a gear 8 engaged by a pinion 9'carrying a pin 10 to enter radial slots in the gear 8, the whole forminga stop motion-of the well-known Geneva type. The pinion 9 is mounted onand driven by a vertical shaft 11 connected throughbeveled gears 12 to ahorizontal counter-shaft'13, on which a spur gear 14; is loosely mountedto mesh with a larger spur gear 15 mounted on and driven by a I secondcounter-shaft 16 actuated by a I sprocket 17 connected through a chainto a sprocket 18 which in turn is actuated from ,a driving gear 19through a disengageable clutch 20. The driving gear 19 runs continuouslyand the machine is started and stopped by the clutch 20, which iscontrolled -by' a clutch lever 21 ,actuated by a pedal 22' under thecontrol of the operator. A catch 23 normally holds the pedal in aposition to cause the clutch. to engage, and a spring 2st tends to movethe pedal when the catch is released and thereby stop the machine.

The carrier 2 is "given a step by step motion at definite intervals bymeans of any suitable. intermittent gearing between the counter-shafts'13 and 16. The preferred .form of intermittent-gearing,shown in detailin Figs. 11, 12 and 13, comprises a clutch member 25, in the form of adisk rigidly connected to the spur gear 14 and having holes I 26 nearthe periphery, which intermittently drives the counter-shaft l3iby meansof a spring-pressed pin 27 arranged to enter one .of the holes 26 andslidably mounted in a second clutch member 28 rigidly fastened totheshaft 13. As long as the pin 27 is in one of the holes 26, the twoclutch members are locked together, and the counter-shaft 16 drives thecounter-shaft 13 through the gears 14 and 15.

Intermittent motion is imparted to the 'counter-shaft 13 byautomatically disconnecting the clutch members 25 and 28 after eachrevolution of the countershaft 13 by any suitable mechanism which movesthe spring-pressed pin 27 out of the holes in the clutch member 25.. Inthe specific arrangement shown in the drawings, the pin 27 has a head 29with an inclined surface which c'ooperates with a cam 30 on the end of acontroller arm 31 carried by a hub mounted on a fixed stud 32 and movedby an actuating arm 33 with a pin in the end -to cooperate with theroove in a face cam 3 L mounted on and driven by the counter-shaft 16.The parts are normally in such a position that the cam 30 holds the pin27 out of engaging position, but when the swell 34 of the face camengages the pin in the end of the actuto revolve at a higher rate ofspeed than the counter-shaft 16. Before the counter-shaft 13 completesone revolution the pin on the end of the actuating arm 33 travels intothe concentric part of the groove in the face cam and moves the cam 30back into a position where, at the end of the revolution of thecounter-shaft 13, the cam engages the inclined surface on the head 29 ofthe, pin 27 and forces the pin out of engagement with the clutch member25, thereby stopping the rotation of the counter-shaft 13, which remainsstationary until the countershaft 16 completes its revolution and byagain throwing the cam 30 out of engaging position permits the pin 27 toengage the clutch member 25. As a result of this construction thecounter-shaft 13 makes one revolution at a-considerably higher speedthan the counter-shaft 16 and then remains stationary until therevolution of thecounter-shaft 16 is completed.

An atmosphere of forming gas, consisting of nitrogen and hydrogen, ismaintained about the filaments during the time they are being heated andformed. The supply-of forming gas may be delivered to each recep= aninlet pipe 35 and escapes through an outlet pipe 36, both of these pipes being con nected to ports in the valve disk 5 in the manner shown inFig. 4. The forming gas is supplied to the treating receptacles througha supply port 37 in the valve seat 6, shownin Fig. 5, and is led throughthe receptacles bymeans of a series of bridging ports 38 in the valveseat 6 arranged to cooperate with the ports in thevalve disk 5 andconnect the out let and inlet pipestof the receptacles to form achannelthrough which the gas can flow fromone receptacle to the next, with theoutlet pipe of-the last receptacle connected to an outlet ort 39 inthevalve seat- 6. The pressure 0 the gas'in the receptacles may becontrolled in any suitable way, preferably by varying the back pressureat the outlet port by means of a throttle valve or pinch cock 40,therebyinsuring a pressure above atmosphere in each receptacle andovercoming the eflect of any leaks in the valve or receptacles. Thecourse of the forming gas through the treating receptacles is best shownin Fig. 20, in which the parts that move are shown in dotted lines andin which the receptacle at A is' in the loading position, while thereceptacle at B containing a rawfilamentis connected to the outlet port39 and also to the supply port 37 through the other receptacles betweenit and the receptacle at J which contains a finished filament, andreceives the forming gas from the supplyv port- 37 connected to a supplypipe 41, purifying cells 42 containing sulfuric acid, and a flowindicator 43. The valve is packed by oil introduced by an oil pipe 44into concentric grooves 45 near the center and the circumference of thevalve seat 6, as shown in Fig. 5. As the valve disk ing through andacting on allot the filaments inthe other receptacles, flows through Band washes'out any air. which entered the receptacles when it was openedat A. This washing action continues at C, so when position Dis reachedpractically all the air is washed out and in this position the filament.is first heated with current. A flow indicator 43 connected to theoutlet port 39 enables the operator to control very accurately theamount of ceptacles.

In order to facilitate the 'o erators work in removing and replacinglaments, each receptacle is preferably made to swing back outof'the way'to-aflo'rd free access to the filament. In the" particular arrangementgas flowing through the reshown in the drawings, the forming receptacle3 is made in the form .of an inverted cylinder open at the bottom andcotiperating with a closure 46 of rubber or similar material which formspart of the filament holder and makes an air-tight joint w-iththe loweredge of the receptacle. Each receptacle, which has guides 47 inengagement with the two guide rods 48 mounted on the movable carrier 2can be raised to the position shown in Fig. 2, where it is caught andheld by the spring catch 49 mounted on the standard 7 and arranged tohold the receptacle in such a position that the filament can be'easilyeached by the operator. g

The filament is carried in proper position in the forming receptacle bya filament holder "comprising *the closure 46 and a standard 50,provided with two notched sockets 51 insulated from each other andshaped to engage and hold lugs on thefila ment clamps 52, which engagethe ends of the filaments 53, as shown in Fig. 7 and are made of metaltolead the heating current through the filament while it is beingformed. The current is supplied to the clamps and the filament throughleads 54;

to a .brush 55 one of which is connected mounted on and movable with thecarrier 2, as-shown in Figs. 17. and 20, and in engagement with a seriesof contacts 56 mounted on the stationary partof the automatic switch 4.The contacts 56 are connected a stationary slip ring 62 connectedthrough the switches 59 and 60 to the supply circuit. As a result ofthese connections, the current flows through the filament. in eachforming receptacle as long as the brush .55 corresponding to thatreceptacle is in engagement with one of the stationary contacts 56, andthe amount of current'through the filament in each position isdetermined by the amount of esistance 57 in series with the contact 56corresponding to that position. In the machine shownfive separate.circuits are used to heat the filaments and are adjusted togive thesmallest current in'the first position and-the greatest current inthelast position, the filament being progressively transferred from onecircuit to the next. I also contemplate maintaining each filament; in anuninterrupted circuit until the forming of -the filament complete, therequired variations in temperature being secured by agt omaticallyvaryin the amount of current in the circuit. T e .f stationary. part ofthe switch 4-,Ias'shown in Figs. 17

and 20, is in the form-of an disk,

"f ds v .in theiform of ratchet teeth over which the brushes 55 slidelike pawls. This arrangement insures a sliding contact between the brush55 and-the contact 56 and also insures a quick breakof the circuitthrough the filament as the brush snaps from one contact to the next.

Inv the machine shown in the drawings, five fixed contacts are provided,and as a result five filaments are being heated during the operation ofthevmachine. As shown in- Fig. 20 the filaments'in the receptacles inpositions D, E, F, G and H are-subjected to the heating current whilethe filaments in. receptacles B,'C, I and- J do not receive current.

The amount of current flowing. through thefilament in each position ofthe carrier. 2 cancbe independently regulated by means of the adjustableresistances 57, which, as shown in Figs. 14 and 15, consist'pf two coils63 of resistance wire wound on any suitable support and connected by abridging piece 64: shifted by an adjusting screw 65 to vary theresistance in the circuit. In order to enable the operator to calibratethe resistances 57 and determine the proper amount of current flowingthrough the filaments, the leads from all of the resistances pass into aplug switch box shown more in detail in Figs. 18 and-.19, and whichconsists of an, insulating box containing as many pairs of flexiblecontacts'66 as there are circuits through the filaments in the treatingmachine.

The spring contacts 66 are normally in engagement with each other .toclose the circuit through the filaments,

but if it is desired to test any circuit, a test ing plug 67 'made ofinsulation and having contacts onopposite sides is inserted be tween thetwo contacts 66 in the circuit to be tested, and in this manner anammeter 68 is connected in series in the circuit and en-' ables theoperator to determine the exact amou'ntof current flowing through thefila- The operator is provided with a number sockets 51 connected to theleads 54. A

clamp 52 with a filament attached thereto is placed'on the standard 50with the lugs on the clamp in engagement with the recessed blocks 51and'therefore in electrical connection with the leads 54, and thetreating receptacle 3 is then moved down into air-tightv engagement withthe closure 46, as shown in Fig. 7. In the succeeding .operations, whichare best understood fromFig. 20, the recep- 70 tacle w1th the filamenttherem is moved one step in the direction of the arrow in Fig. 20 by theaction of the'intermittent gear, and

comes into position B with its outlet pipe connected to the outlet port39 and its inlet pipe connected to the outlet pipe of the precedingreceptacle. The forming gas, heated inthe preceding receptacles, flowsthrough the receptacle'and washes out any air which may be in thereceptacle. After a predetermined time has elapsed, the intermittentgear again moves the carrier one step in the direction of the arrow andthe receptacle is carried to position C, where it forms one of theseries of receptacles through which the current of forming gas flows andbecomes filledwith an atmosphere free from oxygen.

,The next movement of the carrier 2 shifts the receptacle into positionD where it again forms one of the series of receptacles through whichthe gas is flowing and at the same time the filament is connectedin'circuit to receive the heating current on account of the brush 55connected to this receptacle comi g into engagement with one of thefixed contacts 56 on the automatic switch. During the next fivemovements of 5 the carrier-2, the filament is heated by a current whichis larger at each successive position, theamount of current at eachposition 6 being determined by the adjustable resistance 57corresponding to that position. In

' the first two positions any oxid in the fila ment is reduced to metaland any carbon is removed, while in the remaining positions 5 thefilament is sintered and consolidated. When the receptacle moves fromposition H through positions I and J the gas continues to flow throughit, but the filament is cut off from the heating current and coolsdownin a reducing atmosphere which prevents any oxidation. The receptacleand its contents cool sufficiently to allow safe opening and handlingwhile passing through these two positions to position A, where theoperator is stationed. Whenthe receptacle has completed the circuit andreturns to position A,

it is cut oil both from the supply of gas and from the, current throughthe filament, the operator lifts the receptacle 3 into the positionshown in Fig. 2, removes the completed filament, and replaces it'with araw filament. The operator removes and replaces the filaments from eachforming receptacle as it stops'in position A, and the operation abovedescribed is repeated.

If the operator desires at any time to adjust the amount of heatingcurrent flowing, through the filament in' any position, the attachingplug 67 is inserted between the proper contacts inthe plug switch box 58justable resistances 57.

My invention maybe embodied in many other forms than that shown anddescribed, and I therefore do not wish to be restricted to the exactform shown but intend to cover by the appended claims all changesandmodifications within the spirit and scope of my invention.

What I claim as" new anddesire to secure trolling means for varying saidconnections tocause a stream of fluid to flow through some of saidreceptacles, and to make each receptacle in turn one of those through-which the stream of fluid flows.

3. In a filament machine, the combination ofa plurality of receptaclesfor filaments, connections whereby a .stream of fluid may be passedthrough said receptacles, and controlling means for varying saidconnections to pass a stream of fluid through some of said receptaclesand to disconnect one receptacle from the stream of fluld and,

simultaneously connect another receptacle to said stream, wherebyv thenumber of receptacles traversed by the stream of fluid remains constant.

4'. In a filament machine, the combination of a plurality of receptaclesfor filaments, connections whereby a stream of fluid may be passedthrough said receptacles, and means for'varying said connections tocause each receptacle in turn to form one of a number less than thewhole and traversed in succession by a stream of fluid and then in turnto be disconnected fromthe stream of in succession, and controllingmeans for varying saidconnections to cause the stream of fluid to flowin succession through a part of said receptacles and for cutting off theremainder of said receptacles from the stream of fluid.

6. An apparatus for treating filaments comprising a plurality offilament receptacles, means for maintaining a flow of fluid through aseries consisting of part of said receptacles, and means for heating thefilaments in some of said receptacles while the fluid is'flowing throughthem.

7. An apparatus 'for treating filaments comprising a plurality offilament receptacles, means for maintaining a flow of fluid through aseries consisting of part .of said receptacles, and means for passingcurrent through the filaments in some of the intermediate receptacles ofthe series.

8. An apparatus for treating filaments comprising a plurality offilament receptacles, means for maintaining a flow of fluid through aseries consisting of part of said receptacles, controlling means forvarying said connections to cause each receptacle in turn to passthrough the series from first to last successively, and means for passing current through the filament in each receptacle while saidreceptacle is intermediate in the series.

9. An apparatus for treating filaments comprising a plurality offilament receptacles, means for maintaining a flow of fluid throughaseries of 831d receptacles, controlllng means for varylng saidconnections to cause each receptacle in turn to pass through the seriesfrom first to last'successively, and automatic means for passing currentthrough the filaments of some of the intermediate receptacles only andthereby cause the end receptacles of the series to be traversed by fluidwhile no current is passing through th filaments in them. 10. In afilament machine, the combination of a plurality of filamentreceptacles,connections for maintaining a flow of fluid through a part of saidreceptacles in'succession, and means actuated in timed relation to saidcontrolling means for successively connecting the filament in eachreceptacle to different circuits whileeach receptacle is traversed bythe current of fluid. r

11. In a filament machine, thecombination of a plurality of filamentreceptacles, connect-ions for causing a stream of fluid to traverse aportion of said receptacles in succession, a plurality of independentelectric circuits forsupplying diflerent amounts of current to afilament, and means for connecting each filament to each of saidcircuits in 1.

succession while the receptacle containing the filament is-traversed bythe fluid.

12. In a filament machine, the combmation of a plurality of filamentreceptacles,

circuit independently of the others, and

- means for connecting the filament in each of matically connecting thefilament in each of said receptacles to the other side'o-f said circuitand to each of said leads in succession while the receptacle is movingthrough said fraction of its path.

14. Ina filament machine, the combination 01:: a rotatable carrier, aplurality of filament receptacles mounted on said carrier, meanscontrolled by said carrier forcausing fluid to flow through a part onlyof said receptacles, and automatic means actuated by said carrier forheating the filaments in a part only of the receptacles traversed byfluid and during the time said receptacles are traversed by the fluid.

15. In a filament machine, the combination of a rotatable carrier, aplurality of filament receptacles mounted on said carrier, -meanscontrolled by said carrier for heating the filaments in some ofsaidreceptacles, and automatic means controlled by said carrier for passinga stream of fluid through said receptacles, while the filaments in saidreceptacles are being heated and while the filaments are being cooled.

- i 16. In a filament machine, the combina-' tion of a movable carrier,a plurality of filament receptacles mounted thereon, -connec tionswhereby a stream of fluid may be passed in succession through thosereceptacles which are between predetermined points in their path ofmovement, thedistance be-' tween said points being only a fraction ofthe travel of each receptacle, a valve actu ated by said carrier to passfluid through said receptacles successively during their travel betweensaid points, and automatic means controlled by said carrier for heating17. In a filament machine, the combination of a rotatable carrier, aplurality of filament receptacles mounted on said carrier,

means controlled by said carrier for causing fluid to traverse a part ofsaid receptacles in succession while the remainder of said receptaclesare cut ofi from the supply of fluid, and automatic means controlled bysaid carrier for heating the filaments in a part of those receptacleswhich are traversed by fluid. 18. In a filament machine, the combinationof a filament receptacle having an inlet and outlet, means for supplyingthe inlet of said receptacle with a fluid under, substantially constantpressure, and means for throttling at will the outlet of said receptacleto vary the pressure of fluid within said receptacle. 7 19. In afilament machine, the combination of a plurality of filamentIrece'ptacles, means for passing fluid through said'receptacles insuccession to a common outlet, and

means for throttling said common outlet to vary the'pres'sure' withinall of said receptacles.

20. In a filament machine, the combination of a filament receptacle,means for sup plying said receptacle with fluid under pres sure, adistributing valve for admitting fluid to and releasing fluid from saidreceptacle, and means for at will partially obstructing the escape offluid from said 'valve to vary the pressure'within said receptacle.

21. Ina filament machine, the combination of a-plurality offilamentreceptacles each having an inlet and an outlet, means forconnecting said receptacles to a source of fluid under pressure to causefluid to flow through'them in succession, and means for at willpartially obstructing the escape of fluid from saidr'eceptacles'tocontrol the pressure of the fluid within said receptacles. In witnesswhereof, I have hereunto set my hand this 4th day of May, 1908.

JOHN W. HOWELLK Witnesses J. HARRY ELKINs,

c. a. owns

